Study Results on Delta-V High-Precision Technology to Improve QZSS Positioning Service Availability

Toshitaka Sasaki, Erika Myojin, Akihiro Matsumoto, Motohisa Kishimoto, Naoki Toshimitsu, Yo Kawashima

Abstract:	As of April 2026, the Quasi-Zenith Satellite System (QZSS) provides satellite positioning services with five satellites: QZS-2, 3, 4, 1R, and 6. QZS-7 is scheduled to be launched in 2026, and the Cabinet Office plans to begin operations with six satellites by the end of the year. QZSS has three orbits: quasi-zenith (QZO: QZS-2, 4, 1R), quasi-geostationary (QGEO: QZS-7), and geostationary (GEO: QZS-3, 6). Satellites in QZO and QGEO perform orbit maintenance operation approximately once every six months, while GEO satellites execute orbit maintenance operation approximately once every 22 days. When QZSS performs orbit maintenance operation, it suspends satellite positioning services for about one and a half days. Studies have shown that significantly improving GEO satellites’ availability can be achieved by realizing Delta-V High-Precision Technology and using observation data during orbit maintenance operation period for orbit determination. This paper describes the design results of attitude and orbit control system (AOCS) that achieves high-precision orbit maneuvering, leading to improve the next-generation QZSS availability, and the results of studies on shortening the orbit determination convergence time after orbit maintenance operation for GEO, which have a particularly high effect on improving availability.
Published in:	Proceedings of the ION 2026 Pacific PNT Meeting April 13 - 16, 2026 Hilton Waikiki Beach Honolulu, Hawaii
Pages:	156 - 165
Cite this article:	Sasaki, Toshitaka, Myojin, Erika, Matsumoto, Akihiro, Kishimoto, Motohisa, Toshimitsu, Naoki, Kawashima, Yo, "Study Results on Delta-V High-Precision Technology to Improve QZSS Positioning Service Availability," Proceedings of the ION 2026 Pacific PNT Meeting, Honolulu, Hawaii, April 2026, pp. 156-165. https://doi.org/10.33012/2026.20641
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